Can Blender Make 2D Flash Animations? (Like Adobe Animate)
Since blender is a 3D modeling and animation program, with a three-dimensional scene you can't get that kind of layer workflow with Z ordering, "background" and "foreground" objects, or layer locking. That is simply not how a 3D scene works.

That being said Blender is fully capable of doing 2D animations, you simply physically stack your objects one above the other, in Z direction (or any other axis that is convenient to you) and you can use the outliner to lock whichever objects you don't want to select or want fixed in the scene. You can also lock their individual transforms if you want them selectable but unmovable.

You can use regular objects and constrains or rigging or whatever 3D method of animation is most comfortable to you, but "constrained" to a 2D plane, which should even simplify things. You can then easily render everything from an orthographic camera placed directly above all objects.

I have never used Adobe Animate but layers in blender work a bit differently, you can either use groups and the outliner to control object visibility and selectability en-mass, or you can get some cad-like layer management with third party addons like VTools Object Layer Manager

As of Blender 2.8#, the already existing Grease Pencil feature has been substantially improved, and includes a lot of new features and functionality. Grease Pencil objects are capable of being animated, rigged and work very close to bi dimensional objects, with brushes, fills and a digital painting workflow.

You can also add modifiers and effects to them, and use the new 2.8 collection system to organize and manage them.